Changes to ghc

Changes to ghc:
commit 022f8750edf6f413fba31293435dcc62600eab77
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date:   Thu May 15 16:07:04 2014 +0100

    Refactoring around TyCon.isSynTyCon

    * Document isSynTyCon better
    * Add isTypeSyonymTyCon for regular H98 type synonyms
    * Use isTypeSynonymTyCon rather than isSynTyCon where
      the former is really intended

    All arose as part of a bug I introduced when fixing Trac #9102,
    thinking that isSynTyCon meant H98 type syononyms.